Q. What is a lee tide?

A. A tide setting to leeward, and with the wind.

Q. How would you tend a vessel in a tideway?

A. A light vessel to leeward, a loaded vessel to windward.

Q. Suppose you were at anchor in a calm, how would you keep the chain clear of the anchor?

A. By heaving in the cable quite short, without tripping the anchor.

Q. What is meant by tide-rode?

A. Swung round by the tide, and riding head to it at anchor.

Q. What is meant by wind-rode?

A. When swung round by the force of the wind at anchor against the tide.

Q. How would you place a kedge in a boat for carrying out?

A. Stock over the stern flukes in the boat, on a plank or spar for canting overboard.

Q. How would you carry out a bower anchor?

A. The crown under the boat with a slip-rope, and a ring-rope over the stern.

Q. You are on a lee shore, on anchorage ground, she will not stay, and there is no room to wear, how would you get her round?

A. Let go the anchor, or, if time allow, unshackle lee-anchor, bend on a warp from the lee-quarter, let go the anchor when the helm is put down, gather in the slack, and hold on the warp; this will check her round. When round, slip the warp.

Q. How would you construct a raft to rescue a crew?

A. Three spare spars lashed as a triangle, with water-casks lashed inside of the triangle, and small, spare spars lashed on top.

Q. Your rudder is carried away; what do you do?

A. If running, lower down the fore-sail, get main sheet in, and fore stay-sail shect to windward. Get three spars and make a triangle; secure a sail over them; bend on a spar; and sling some pieces of iron to the lower spar; bend on a stout warp to the spar; heave over to windward, veer over the hawser, and the vessel will lie-to comfortably while you are rigging a jury-rudder.

Q. You have no time to do this; you are on a lee shore?

A. Get a square top-sail yard; nail a couple of stout boards to one end at right angles to each other; pass it out under the taffrail; lash it amidships; get a luff-tackle on the inboard end; and you will find she will steer, unless a very unhandy vessel. Q. You have no time for this even?

A. Then let go both anchors, and cut away the masts, if she will not ride to it without.

Q. What is a spinnaker?

A. A lofty triangular-shaped sail made of light canvas, used in modern racingyachts instead of a square-sail for running before the wind. The foot of it is extended by means of a long spar called the spinnaker-boom, which works with a goose-neck on the fore-side of the mast.

Q. How do you set and take in a spinnaker?

A. Get the inner end of the boom over the taffrail on the side opposite to that on which you are carrying the main-boom; light it along until the outer end is far enough aft to clear the head-sheets, then launch forward; hook on the topping-lift; bend on a couple of whips purchased to the outer end, lead one forward and the other aft; hoist away on the topping-lift until it takes the weight of the boom; shove it forward until the goose-neck can be shipped in its place on the mast. Bend on the halliards to the head of the sail, and the outer clew to the out-haul on the boom, taking care that it is on the fore side of the topping-lift. Hoist away on the halliards, and at the

same time haul out the clew; when it is chock up to the topmast head, the clew close out and the inner clew fast, slack down your topping lift until the boom is just clear of the rail, and trim with the after-guy. In large vessels it is usual to have another guy from the outer end to the side of the vessel, to keep the boom from rising when the sail is distended by the pressure of the wind. In taking in a spinnaker, top the boom well up, ease in the out-haul, and slack away the halliards at the same time, and gather in the sail as it comes down. Ease away the after-guy until the boom is fore and aft; unship the goose-neck, and stow it along the deck; or the boom may be hoisted up with the topping-lift until it is parallel with the mast.

Q. How would you set it as a jib?

A. Lash a small tail-block on the bowsprit outside the shroud-iron; reeve a rope through it; bend it on to the outer clew of your spinnaker, and haul chock out; belay and hoist away on the halliards; use the balloon-jib sheets for spinnaker-sheets. Q. You have not said anything about the preventer back-stays. What are they? A. Temporary stays leading in yachts from the top-mast head to the quarters. They are used when the jib top-sail or spinnaker is set.

Q. You have spoken several times about ** heaving-to." Now, you are running in a strong gale with heavy sea, and it is necessary to "heave-to" shorten sail, how would you do it so as not to run the risk of having the decks swept?

A. Batten down the hatches, get everybody aft to the main-sheet, watch for a smooth sea, and, as the yacht begins to descend, ease down the helm, and as the vessel comes up to the wind get in the main-sheet foot by foot; haul fore-sheet to windward, lash the helm a lee, and proceed to reduce your canvas.

Q. Suppose you are beating through a crowded channel, with a very light breeze and strong tide, and find you are drifting foul of other vessels; what would you do? A. If the tide was adverse, bring up. If the tide was favorable, I would get the anchor or kedge over to leeward with plenty of chain, bend on a stout hawser to the chain within a couple of feet of the anchor, and lead it aft to the quarter. Put the helm down and let her come-to; when she begins to lose way, let go the anchor to leeward and haul on the hawser; when she is fairly round, slip your cable and haul in the anchor over the stern.

Q. You are trying to claw off a leeshore in a gale under storm-jib and three reefed main-sail, and your vessel persists in running off her helm in the squalls; what would you do?

A. Get everything below that was at all weighty into the fore-peak, and sail her with the head-sheets very flat.

PRACTICAL NOTES ON STEAM-ENGINEERING,

BY GEORGE W. BAIRD,

PASSED ASSISTANT ENGINEER, U.S.N.

STEAM.

BY saturated steam we understand the steam to be just sufficiently heated to continue in the form of vapor. Applying heat to saturated steam converts the small particles of water held in suspension into steam, and, when this process is complete, a further application of heat causes superheating, provided the steam is not confined so as to increase its pressure; but, if saturated steam be cooled, a part of it will condense.

There are two distinct phases in the conversion of water into steam, and to readily comprehend these we will take them in their order. A thermal unit is the amount of heat required to raise one pound of water one degree at its maximum density (39° F.), and this is practically constant for any calculation with the steam-engine, though it increases slightly with temperature. Now, if heat be applied to a pound of water at the freezing-point (32° F.), and continued until the temperature reaches the boiling-point (212° F.), there will be consumed (212-32) 180 thermal units. The water absorbing heat, evaporation now commences, and if the pressure be not increased above the atmosphere, the water will be entirely evaporated without indicating any increase of temperature. But to evaporate this pound of water, after raising it to the boiling-point, there will be consumed 966 thermal units. This heat is expended in overcoming the resistance of the particles of the water to the repulsion incident to the change into vapor, and also to the work of expansion against the resistance of the atmosphere in which it is formed, so that the total expenditure of heat in changing a pound of water at 32° F. into steam at 212° F. is (180+966)1,146 units. The quantity 966 is called the latent heat of vaporization, and is determined by subtracting the sensible from the total heat.